An artist's conception of a joint high speed vessel at sea with railgun installed. The Navy will test such a combination this summer. (Navy illustration)

The Navy will display electromagnetic railgun prototypes on the joint high speed vessel Millinocket in San Diego later this summer, and a manually loaded, single-shot live-fire demonstration aboard the vessel is scheduled for 2016.

Two years after that, officials plan an automatically loaded, multiround live fire of what the chief of naval research calls “an incredible deterrent capability.”

The physics involved seem to support Rear Adm. Matthew Klunder’s assessment. The railgun uses a 32-megajoule system — in energy lingo, 1 megajoule is roughly equivalent to the kinetic energy of a 1-ton object moving at 100 mph.

That energy can send a 23-pound projectile to distances greater than 100 miles at speeds topping Mach 7 (better than 5,300 mph). And at $25,000 a pop, that round comes in at one-hundredth of the cost of existing missile systems.

The inert round can be used in just about any mission set, to include air and ballistic-missile defense. Ships can carry hundreds of rounds without the dangerous burden of gunpowder. And the Army, after seeing performance numbers and observing the railgun in action, has indicated an interest in using the technology for land-based missile defense, Klunder said.

Rear Adm. Bryant Fuller of Naval Sea Systems Command said hundreds of rounds have been fired and the technology “certainly is mature enough” for at-sea demonstration. The demonstrator will not be integrated into the ship.

Because JHSVs are non-combatants, there is no plan to install this system on other ships of the class, officials said. But JHSV was “a great vessel of opportunity” for testing, Fuller said: It has the required cargo and lift capacity, can easily carry the weight and the large, flat flight deck will not require extensive modification.

The program is moving into Phase 2, in which the BAE Systems prototype will incorporate auto-loading and thermal management systems and move from single-shot to multishot capability.